Batteries, in particular lithium-ion cells or batteries, have at least one positive electrode and negative electrode (cathode and anode) that allow the reversible insertion of lithium ions (Li+) (intercalation) or their extraction again (deintercalation). Lithium-ion cells and batteries made up from them by being connected in parallel or in series have to meet stringent requirements in terms of safety, operating behavior and energy density.
According to the prior art, lithium-ion cells may be packaged in aluminum composite foil, known as pouch cells or soft packs, which in present-day technical terminology are also referred to as lithium-ion polymer cells or lithium polymer cells. Further possibilities for enclosing lithium-ion cells with a housing are purely metallic housings, also referred to as hard housings (hardcase housings). There are purely metallic housings of a cylindrical form and of a prismatic form. Purely metallic cell housings for lithium-ion cells, in which the housing must be at a potential, must be electrically insulated on the outside if they are made up as high-voltage batteries. Electrically puncture-proof adhesive tapes, for example polyester-based tapes with acrylic adhesive, or electrical insulating varnishes may be used for this purpose.
Various problems may occur in the adhesive attachment of the electrical insulating layer to the outer metal surface of the cell housing. For instance, there may be instances of detachment of the insulation layers, or inhomogeneities at the applied insulation layer. Moreover, metal particles that can mechanically damage the applied electrical insulation layer may also become attached to the metallic outer surface.